The Birth of Sativex: How GW Pharmaceuticals Developed Cannabis Medicine | Research

The takeaway

GW Pharmaceuticals developed multiple cannabis-based prescription medicines including Sativex (THC:CBD), completing phase III trials showing significant pain reduction in MS and other neuropathic conditions.

Read this if you want to understand how the first cannabis-based prescription medicines were developed and brought to market.

Phase III trials showed significant neuropathic pain reduction; Bayer licensed Sativex

What the researchers found

GW Pharmaceuticals was developing distinct cannabis-based prescription medicines using three delivery systems: sublingual spray, sublingual tablet, and inhaled (non-smoked) forms. Four formulations were being tested: High THC, THC:CBD (narrow ratio), THC:CBD (broad ratio), and High CBD.

Completed phase III trials demonstrated that THC:CBD (narrow ratio) produced statistically significant reductions in neuropathic pain in MS patients and other conditions, with improvements in additional MS symptoms observed. Phase II trials across MS, spinal cord injury, neuropathic pain, peripheral neuropathy, rheumatoid arthritis, and perioperative pain all provided positive results with excellent safety profiles. Bayer AG was licensed for UK commercialization under the Sativex brand name.

Why it matters

This review documented a watershed moment in cannabinoid medicine: the first pharmaceutical company successfully developing standardized cannabis-based prescription drugs through the conventional regulatory pathway. The development of Sativex demonstrated that cannabis could meet pharmaceutical standards for quality, safety, and efficacy.

The numbers in context

Five phase III trials underway. One trial included more than 100 patients with cancer pain. Phase II trials completed across 6 therapeutic areas. UK commercialization licensed to Bayer AG. IND approval for US phase II trials received.

How the study worked

This was a pharmaceutical industry review documenting the development program for GW Pharmaceuticals' cannabis-based medicines, including summaries of completed and ongoing clinical trials across multiple indications.

What this study cannot tell us

This was an industry-produced review that presented the company's development program in favorable terms. Detailed trial data and methodology were not provided. The review was written before most trial results were published in peer-reviewed form.

How to read the evidence

This is a pharmaceutical development review summarizing multiple clinical trials, providing moderate-level evidence through aggregated trial results.

When this study was published

Published in 2003. Sativex was subsequently approved in 25+ countries, and GW was acquired by Jazz Pharmaceuticals in 2021.

The bigger picture

Sativex was eventually approved in multiple countries for MS spasticity, becoming the first cannabis-based pharmaceutical to achieve broad regulatory approval. GW Pharmaceuticals later developed Epidiolex (CBD) for epilepsy. The company was acquired by Jazz Pharmaceuticals in 2021 for $7.2 billion, validating the commercial potential of cannabis-based medicines.

Questions still open

How did the actual market launch timeline compare to the projected 2003 date? Did the security monitoring technology to prevent abuse ever prove necessary or effective?

Common questions

What is Sativex?

Sativex (nabiximols) is a mouth spray containing THC and CBD extracted from cannabis plants. Developed by GW Pharmaceuticals, it was the first cannabis-based prescription medicine to achieve broad regulatory approval, primarily for MS spasticity.

Is Sativex available in the US?

As of this review, GW was seeking US regulatory pathway. Sativex has faced a complex regulatory path in the US and has been approved in many other countries but not the US, where the company's CBD product Epidiolex achieved approval instead.

Read the original research

Cannabis-based medicines--GW pharmaceuticals: high CBD, high THC, medicinal cannabis--GW pharmaceuticals, THC:CBD.

Drugs in R&D, 4(5), 306-9

View on PubMed ↗

Citation

. (2003). Cannabis-based medicines--GW pharmaceuticals: high CBD, high THC, medicinal cannabis--GW pharmaceuticals, THC:CBD.. Drugs in R&D, 4(5), 306-9.